OpenRaiser/Intern-Atlas huggingface dataset:
When Money Learns to Fly: Towards Sensing as a Service Applications Using Bitcoin
Venue: arXiv cs.CY 2014
Year: 2014

Sensing-as-a-Service (S2aaS) is an emerging Internet of Things (IOT) business model pattern. To be technically feasible and to effectively allow for broad adoption, S2aaS implementations have to overcome manifold systemic hurdles, specifically regarding payment and sensor identification. In an effort to overcome these hurdles, we propose Bitcoin as protocol for S2aaS networks. To lay the groundwork and start the conversation about disruptive changes that Bitcoin technology could bring to S2aaS concepts and IOT in general, we identify and discuss the core characteristics that could drive those changes. We present a conceptual example and describe the basic process of exchanging data for cash using Bitcoin.
AMMSE Optimization for Multiuser MISO Systems with Imperfect CSIT and Perfect CSIR
Venue: arXiv cs.IT 2014
Year: 2014

In this paper, we consider the design of robust linear precoders for MU-MISO systems where users have perfect Channel State Information (CSI) while the BS has partial CSI. In particular, the BS has access to imperfect estimates of the channel vectors, in addition to the covariance matrices of the estimation error vectors. A closed-form expression for the Average Minimum Mean Square Error (AMMSE) is obtained using the second order Taylor Expansion. This approximation is used to formulate two fairness-based robust design problems: a maximum AMMSE-constrained problem and a power-constrained problem. We propose an algorithm based on convex optimization techniques to address the first problem, while the second problem is tackled by exploiting the close relationship between the two problems, in addition to their monotonic natures.
Demo Abstract: NILMTK v0.2: A Non-intrusive Load Monitoring Toolkit for Large Scale Data Sets
Venue: arXiv cs.OH 2014
Year: 2014

In this demonstration, we present an open source toolkit for evaluating non-intrusive load monitoring research; a field which aims to disaggregate a household's total electricity consumption into individual appliances. The toolkit contains: a number of importers for existing public data sets, a set of preprocessing and statistics functions, a benchmark disaggregation algorithm and a set of metrics to evaluate the performance of such algorithms. Specifically, this release of the toolkit has been designed to enable the use of large data sets by only loading individual chunks of the whole data set into memory at once for processing, before combining the results of each chunk.
Finite Automata With Restricted Two-Way Motion
Venue: arXiv cs.FL 2014
Year: 2014

We consider finite two-way automata and measure the use of two-way motion by counting the number of left moves in accepting computations. Restriction of the automata according to this measure allows us to study in detail the use of two-way motion for the acceptance of regular languages in terms of state complexity. The two-way spectrum of a given regular language is introduced. This quantity reflects the change of size of minimal accepting devices if the use of two-way motion is increased incrementally. We give examples for spectra, prove uniform upper and lower bounds and study their sharpness. We also have state complexity results for two-way automata with uniformly bounded use of two-way motion.
Automated Discharging Arguments for Density Problems in Grids
Venue: arXiv cs.DM 2014
Year: 2014

Discharging arguments demonstrate a connection between local structure and global averages. This makes it an effective tool for proving lower bounds on the density of special sets in infinite grids. However, the minimum density of an identifying code in the hexagonal grid remains open, with an upper bound of $\frac{3}{7} \approx 0.428571$ and a lower bound of $\frac{5}{12}\approx 0.416666$. We present a new, experimental framework for producing discharging arguments using an algorithm. This algorithm replaces the lengthy case analysis of human-written discharging arguments with a linear program that produces the best possible lower bound using the specified set of discharging rules. We use this framework to present a lower bound of $\frac{23}{55} \approx 0.418181$ on the density of an identifying code in the hexagonal grid, and also find several sharp lower bounds for variations on identifying codes in the hexagonal, square, and triangular grids.
Oblivious Bounds on the Probability of Boolean Functions
Venue: arXiv cs.AI 2014
Year: 2014

This paper develops upper and lower bounds for the probability of Boolean functions by treating multiple occurrences of variables as independent and assigning them new individual probabilities. We call this approach dissociation and give an exact characterization of optimal oblivious bounds, i.e. when the new probabilities are chosen independent of the probabilities of all other variables. Our motivation comes from the weighted model counting problem (or, equivalently, the problem of computing the probability of a Boolean function), which is #P-hard in general. By performing several dissociations, one can transform a Boolean formula whose probability is difficult to compute, into one whose probability is easy to compute, and which is guaranteed to provide an upper or lower bound on the probability of the original formula by choosing appropriate probabilities for the dissociated variables. Our new bounds shed light on the connection between previous relaxation-based and model-based approximations and unify them as concrete choices in a larger design space. We also show how our theory allows a standard relational database management system (DBMS) to both upper and lower bound hard probabilistic queries in guaranteed polynomial time.
The Information Theoretically Efficient Model (ITEM): A model for computerized analysis of large datasets
Venue: arXiv cs.LG 2014
Year: 2014

This document discusses the Information Theoretically Efficient Model (ITEM), a computerized system to generate an information theoretically efficient multinomial logistic regression from a general dataset. More specifically, this model is designed to succeed even where the logit transform of the dependent variable is not necessarily linear in the independent variables. This research shows that for large datasets, the resulting models can be produced on modern computers in a tractable amount of time. These models are also resistant to overfitting, and as such they tend to produce interpretable models with only a limited number of features, all of which are designed to be well behaved.
Optimal Ternary Constant-Composition Codes with Weight Four and Distance Six
Venue: arXiv cs.IT 2014
Year: 2014

The sizes of optimal constant-composition codes of weight three have been determined by Chee, Ge and Ling with four cases in doubt. Group divisible codes played an important role in their constructions. In this paper, we study the problem of constructing optimal ternary constant-composition codes with Hamming weight four and minimum distance six. The problem is solved with a small number of lengths undetermined. The previously known results are those with code length no greater than 10.
A connected 3-state reversible Mealy automaton cannot generate an infinite Burnside group
Venue: arXiv cs.FL 2014
Year: 2014

The class of automaton groups is a rich source of the simplest examples of infinite Burnside groups. However, there are some classes of automata that do not contain such examples. For instance, all infinite Burnside automaton groups in the literature are generated by non reversible Mealy automata and it was recently shown that 2-state invertible-reversible Mealy automata cannot generate infinite Burnside groups. Here we extend this result to connected 3-state invertible-reversible Mealy automata, using new original techniques. The results provide the first uniform method to construct elements of infinite order in each infinite group in this class.
Automatic Retraction and Full Cycle Operation for a Class of Airborne Wind Energy Generators
Venue: arXiv cs.SY 2014
Year: 2014

Airborne wind energy systems aim to harvest the power of winds blowing at altitudes higher than what conventional wind turbines reach. They employ a tethered flying structure, usually a wing, and exploit the aerodynamic lift to produce electrical power. In the case of ground-based systems, where the traction force on the tether is used to drive a generator on the ground, a two phase power cycle is carried out: one phase to produce power, where the tether is reeled out under high traction force, and a second phase where the tether is recoiled under minimal load. The problem of controlling a tethered wing in this second phase, the retraction phase, is addressed here, by proposing two possible control strategies. Theoretical analyses, numerical simulations, and experimental results are presented to show the performance of the two approaches. Finally, the experimental results of complete autonomous power generation cycles are reported and compared with first-principle models.
Learning Algorithm for Relation-Substitutable Context-Free Languages
Venue: arXiv cs.FL 2014
Year: 2014

We generalized the class of $k,l$-substitutable languages (Yoshinala, 2008). Each language in the generalized class is closed under a good substitutability. The substitutability is defined by a recognizable equivalence relation. We show the convergence of our generalized learning algorithm. The size of the characteristic sample is smaller than Yoshinaka's.
Enabling Incremental Query Re-Optimization
Venue: arXiv cs.DB 2014
Year: 2014

As declarative query processing techniques expand in scope --- to the Web, data streams, network routers, and cloud platforms --- there is an increasing need for adaptive query processing techniques that can re-plan in the presence of failures or unanticipated performance changes. A status update on the data distributions or the compute nodes may have significant repercussions on the choice of which query plan should be running. Ideally, new system architectures would be able to make cost-based decisions about reallocating work, migrating data, etc., and react quickly as real-time status information becomes available. Existing cost-based query optimizers are not incremental in nature, and must be run "from scratch" upon each status or cost update. Hence, they generally result in adaptive schemes that can only react slowly to updates. An open question has been whether it is possible to build a cost-based re-optimization architecture for adaptive query processing in a streaming or repeated query execution environment, e.g., by incrementally updating optimizer state given new cost information. We show that this can be achieved beneficially, especially for stream processing workloads. Our techniques build upon the recently proposed approach of formulating query plan enumeration as a set of recursive datalog queries; we develop a variety of novel optimization approaches to ensure effective pruning in both static and incremental cases. We implement our solution within an existing research query processing system, and show that it effectively supports cost-based initial optimization as well as frequent adaptivity.
Finding the Core-Genes of Chloroplasts
Venue: arXiv cs.CE 2014
Year: 2014

Due to the recent evolution of sequencing techniques, the number of available genomes is rising steadily, leading to the possibility to make large scale genomic comparison between sets of close species. An interesting question to answer is: what is the common functionality genes of a collection of species, or conversely, to determine what is specific to a given species when compared to other ones belonging in the same genus, family, etc. Investigating such problem means to find both core and pan genomes of a collection of species, \textit{i.e.}, genes in common to all the species vs. the set of all genes in all species under consideration. However, obtaining trustworthy core and pan genomes is not an easy task, leading to a large amount of computation, and requiring a rigorous methodology. Surprisingly, as far as we know, this methodology in finding core and pan genomes has not really been deeply investigated. This research work tries to fill this gap by focusing only on chloroplastic genomes, whose reasonable sizes allow a deep study. To achieve this goal, a collection of 99 chloroplasts are considered in this article. Two methodologies have been investigated, respectively based on sequence similarities and genes names taken from annotation tools. The obtained results will finally be evaluated in terms of biological relevance.
On the Category of Group Codes
Venue: arXiv cs.IT 2014
Year: 2014

For the category of group codes, that generalizes the category of linear codes over a finite field, and with the generalized notions of direct sums and ndecomposable group codes, we prove that every MDS non trivial code, every perfect non trivial code, and every constant weight nondegenerate group code are indecomposable. We prove that every group code is a direct sum of indecomposable group codes, and using this result we obtain the automorphism groups of any group code in terms of its decomposition in indecomposable components. We conclude with the determination of the structure of decomposable cyclic group codes.
Multiband Spectrum Sensing: Challenges and Limitations
Venue: arXiv cs.IT 2014
Year: 2014

Multiband spectrum access presents the next generation of cognitive radio networks (CRNs), where multiple bands are sensed and accessed to enhance the network's throughput, improve spectrum's maintenance, and reduce handoff frequency and data transmission interruptions due to the activities of the primary users. In this paper, we discuss the challenges and limitations of the major multiband spectrum sensing techniques. Particularly, we highlight the edge-detection problem and examine several issues of the state-of-the-art wavelet-based techniques. We also study the compressive sensing problem. Finally, we highlight the promises of utilizing the angle-domain for the CRNs.
Modelling Correlated Mobility
Venue: arXiv cs.NI 2014
Year: 2014

When nodes in a mobile network cluster together or move according to common external factors (e.g., cars that follow the road network), the resulting contact patterns become correlated. In this work we address the question of modelling such correlated mobility movements for the analysis of intermittently connected networks. We propose to use the concept of node colouring time to characterise dynamic node contact patterns. We analyse how this model compares to existing work, and demonstrate how to extract the relevant data from actual trace files. Moreover, we show how this information can be used to derive the latency distribution of DTN routing protocols. Our model achieves a very good fit to simulated results based on real vehicular mobility traces, whereas models which assumes independent contacts do not.
Anatomy of the Internet Peering Disputes
Venue: arXiv cs.NI 2014
Year: 2014

Internet peering disputes have had an impact on the Internet AS-graph. As a result, the customers of the ASes often suffer because they cannot reach to the all of the Internet. There is a lack of study of the disputes that have taken place so far, even though each dispute is individually well understood. In this paper, we collect data on 26 disputes from from various resources, categorise them in a systemic manner to understand them from geographical and temporal point of views. There are some ASes that are more involved in disputes than others. In the end, we conclude we need to collect more data as it would be more interesting to have data on the Internet peering disputes around the world.
Adversary Model: Adaptive Chosen Ciphertext Attack with Timing Attack
Venue: arXiv cs.CR 2014
Year: 2014

We have introduced a novel adversary model in Chosen-Ciphertext Attack with Timing Attack (CCA2-TA) and it was a practical model because the model incorporates the timing attack. This paper is an extended paper for 'A Secure TFTP Protocol with Security Proofs'. Keywords - Timing Attack, Random Oracle Model, Indistinguishabilit, Chosen Plaintext Attack, CPA, Chosen Ciphertext Attack, IND-CCA1, Adaptive Chosen Ciphertext Attack, IND-CCA2, Trivial File Transfer Protocol, TFTP, Security, Trust, Privacy, Trusted Computing, UBOOT, AES, IOT, Lightweight, Asymmetric, Symmetric, Raspberry Pi, ARM.
E-Business Experiences with Online Auctions
Venue: arXiv cs.CY 2014
Year: 2014

Online auctions are among the most influential e-business applications. Their impact on trading for businesses, as well as consumers, is both remarkable and inevitable. There have been considerable efforts in setting up market places, but, with respects to market volume, online trading is still in its early stages. This chapter discusses the benefits of the concept of Internet marketplaces, with the highest impact on pricing strategies, namely, the conduction of online business auctions. We discuss their benefits, problems and possible solutions. In addition, we sketch actions for suppliers to achieve a better strategic position in the upcoming Internet market places.
Modeling Language Variability
Venue: arXiv cs.SE 2014
Year: 2014

A systematic way of defining variants of a modeling language is useful for adopting the language to domain or project specific needs. Variants can be obtained by adopting the syntax or semantics of the language. In this paper, we take a formal approach to define modeling language variability and show how this helps to reason about language variants, models, and their semantics formally. We introduce the notion of semantic language refinement meaning that one semantics variant is implied by another.
The Amsterdam Manifesto on OCL
Venue: arXiv cs.SE 2014
Year: 2014

In November 1998 the authors participated in a two-day workshop on the Object Constraint Language (OCL) in Amsterdam. The focus was to clarify issues about the semantics and the use of OCL, and to discuss useful and necessary extensions of OCL. Various topics have been raised and clarified. This manifesto contains the results of that workshop and the following work on these topics. Overview of OCL.
MontiCore: Modular Development of Textual Domain Specific Languages
Venue: arXiv cs.SE 2014
Year: 2014

Reuse is a key technique for a more efficient development and ensures the quality of the results. In object technology explicit encapsulation, interfaces, and inheritance are well known principles for independent development that enable combination and reuse of developed artifacts. In this paper we apply modularity concepts for domain specific languages (DSLs) and discuss how they help to design new languages by extending existing ones and composing fragments to new DSLs. We use an extended grammar format with appropriate tool support that avoids redefinition of existing functionalities by introducing language inheritance and embedding as first class artifacts in a DSL definition. Language embedding and inheritance is not only assisted by the parser, but also by the editor, and algorithms based on tree traversal like context checkers, pretty printers, and code generators. We demonstrate that compositional engineering of new languages becomes a useful concept when starting to define project-individual DSLs using appropriate tool support.
System Model Semantics of Class Diagrams
Venue: arXiv cs.SE 2014
Year: 2014

Defining semantics for UML is a difficult task. Disagreements in the meaning of UML constructs as well as the size of UML are major obstacles. In this report, we describe our approach to define the semantics for UML. Semantics is defined denotationally as a mapping into our semantics domain called the system model [4, 5, 6]. We demonstrate our approach by defining the semantics for a comprehensive version of class diagrams. The semantics definition is detailed for UML/P class diagrams, a variant of class diagrams which restricts the use of a few methodologically and semantically involved concepts. Class diagrams are well-known and rather easy to understand and thus perfect to examine the usability of the system model for precise semantic mappings.
System Model Semantics of Statecharts
Venue: arXiv cs.SE 2014
Year: 2014

In this report, semantics for Statecharts is defined based on a mathematical model of object systems called "system model". The semantics definition is detailed for UML/P Statecharts, a variant of Statecharts which restricts the use of a few methodologically and semantically difficult concepts. After transforming full UML/P Statecharts to simplified but semantically equivalent Statecharts, the semantics is defined denotationally as a mapping into the system model. It is also sketched how already existing Statechart semantics can be mapped into the system model. This report follows, in which we introduced our approach in detail and defined semantics for UML class diagrams.
On Uniform Capacitated $k$-Median Beyond the Natural LP Relaxation
Venue: arXiv cs.DS 2014
Year: 2014

In this paper, we study the uniform capacitated $k$-median problem. Obtaining a constant approximation algorithm for this problem is a notorious open problem; most previous works gave constant approximations by either violating the capacity constraints or the cardinality constraint. Notably, all these algorithms are based on the natural LP-relaxation for the problem. The LP-relaxation has unbounded integrality gap, even when we are allowed to violate the capacity constraints or the cardinality constraint by a factor of $2-ε$. Our result is an $\exp(O(1/ε^2))$-approximation algorithm for the problem that violates the cardinality constraint by a factor of $1+ε$. This is already beyond the capability of the natural LP relaxation, as it has unbounded integrality gap even if we are allowed to open $(2-ε)k$ facilities. Indeed, our result is based on a novel LP for this problem. The version as we described is the hard-capacitated version of the problem, as we can only open one facility at each location. This is as opposed to the soft-capacitated version, in which we are allowed to open more than one facilities at each location. We give a simple proof that in the uniform capacitated case, the soft-capacitated version and the hard-capacitated version are actually equivalent, up to a small constant loss in the approximation ratio.
On the Stability of Sparse Convolutions
Venue: arXiv cs.IT 2014
Year: 2014

We give a stability result for sparse convolutions on $\ell^2(G)\times \ell^1(G)$ for torsion-free discrete Abelian groups $G$ such as $\mathbb{Z}$. It turns out, that the torsion-free property prevents full cancellation in the convolution of sparse sequences and hence allows to establish stability in each entry, that is, for any fixed entry of the convolution the resulting linear map is injective with an universal lower norm bound, which only depends on the support cardinalities of the sequences. This can be seen as a reverse statement of the famous Young inequality for sparse convolutions. Our result hinges on a compression argument in additive set theory.